Shale shaker with stair-stepped arrangement of screens and methods of using same, and methods of retrofitting shale shakers

Abstract

A shale shaker that includes a base, a basket, a vibrator interconnected with the basket, and two shaker screens releasably mounted on the basket, with the first shaker screen having a discharge end, with the second screen having a first end with a seal abutted thereto, with the second screen positioned such that the seal is positioned below the first shaker screen, and positioned so that discharge from the first screen will not discharge onto the seal.

Description

RELATED APPLICATION DATA[0001]Not applicable.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to methods of and apparatus for the processing of drilling fluids. In another aspect, the present invention relates to drilling fluid processing apparatus and methods for processing drilling fluids. In even another aspect, the present invention relates to shale shakers for processing drilling fluids, and to methods of processing drilling fluids with shale shakers. In still another aspect, the present invention relates to shale shakers having a stair-stepped (or cascade) shaker screen deck arrangement, and to methods of processing drilling fluids using such shale shakers, and to methods of retrofitting shale shakers. In yet another aspect, the present invention relates to shale shakers having a stair-stepped shaker screen deck arrangement arranged in a manner that will protect the seals from the direct flow of fluids / solids, and to methods of proc...

AI Technical Summary

Benefits of technology

[0031]It is another object of the present invention to provide for improved shale shakers to reduce or eliminate solids by passing the seals between abutted shaker screens arranged in a deck.

[0032]It is even another object of the present invention to provide for improved shale shakers to reduce or eliminate the exposure of the screen seals to the processed fluids and / or solids.

[0033]It is still another object of the present invention to provide for improved shale shakers to reduce or eliminate the degradation of the screen seals in the operation of the shale shaker.

Problems solved by technology

The drilling mud may also carry lost circulation materials for sealing porous sections of the borehole.

The drilling mud contains inter alia expensive synthetic oil-based lubricants and it is normal therefore to recover and re-use the used drilling mud, but this requires inter alia the solids to be removed from the drilling mud.

If drilled solids are not removed from the mud used during the drilling operation, recirculation of the drilled solids can create viscosity and gel problems in the mud, as well as increasing wear in mud pumps and other mechanical equipment used for drilling.

The frame of the vibrating screen is resiliently suspended or mounted upon a support and is caused to vibrate by a vibrating mechanism, e.g. an unbalanced weight on a rotating shaft connected to the frame.

A particular problem is encountered when two or more screens are abutted together in a linear arrangement to form a deck of screens.

In addition, between the corrosive action of the vibrating particles against the seals abrading the seals, and the harsh effect of the oil based fluids eating away on the seals, the integrity of the seal is slowly compromised.

This too results in a certain amount of particles by-passing the seals and falling through.

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